Light emitting device having opening for extracting light and method for manufacturing light emitting device having opening for extracting light

ABSTRACT

A light emitting device includes a flip-chip mounted type light emitting element, a phosphor-containing member, and a first reflecting member. The flip-chip mounted type light emitting element has a pair of electrodes disposed on a bottom surface side. The phosphor-containing member is provided at least above the light emitting element and separated from the light emitting element. The first reflecting member is configured to cover the phosphor-containing member. An opening is in at least one of side faces of the light emitting device, the opening extracting light emitted from the light emitting element and light whose wavelength is converted by the phosphor-containing member.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 14/445,165, filed on Jul. 29, 2014. Thisapplication claims priority to Japanese Patent Application No.2013-157729, filed on Jul. 30, 2013. The entire disclosures of U.S.patent application Ser. No. 14/445,165 and Japanese Patent ApplicationNo. 2013-157729 are hereby incorporated herein by reference.

BACKGROUND OF THE INTENTION

1. Field of the Invention

Technical Field

The present disclosure relates to a light emitting device and a methodfor manufacturing a light emitting device.

2. Description of Related Art

Light emitting diodes (LEDs) and other such semiconductor light emittingelements are compact, have good power efficiency, emit light in vividcolor, do not burn out, because they are semiconductor elements, haveexcellent initial drive characteristics, and are resistant to vibrationsand being repeatedly switched on and off.

Because of these outstanding features, light emitting devices in whichsemiconductor light emitting elements are installed as a light sourceare utilized, in various structures adapted to the application, as lightsources for ordinary consumer products, such as lighting devices andbacklights for liquid crystal displays (LCDs).

Usually, a light emitting device in which a semiconductor light emittingelement is used as a light source is similar to an ordinarysemiconductor element in that it is manufactured by installing asemiconductor light emitting element (hereinafter referred to simply asa “light emitting element”) on a substrate provided with wiring forsupplying drive current to the light emitting device, electricallyconnecting the light emitting element to this wiring, and sealing theelement with a resin.

This resin can be made from a light-transmissive material so as totransmit the light emitted by the light emitting element.

Furthermore, there are known light emitting devices in which a phosphoris contained in this transmissive resin (sealing member), so as to emitlight with not just the color of light emitted by the light emittingelement, but also mixed colors of the color of light emitted by thelight emitting element and the color of light that has undergonewavelength conversion by the phosphor.

For example, JP2001-196640A discloses a manufacturing method of a lightemitting device that includes affixing a prepared reflector having acavity with an opening for resin injection to a wiring board with alight emitting element mounted thereon, filling the cavity of areflector with a transmissive resin through the opening and hardeningthe resin. In the reflector, the cavity covers the light emittingelement so that a light from the light emitting element is reflected onthe inner wall faces of the cavity.

Also, JP2006-245020A discloses a light emitting device in which an LEDchip, a phosphorescent substance that emits light of a differentwavelength from that of the light emitted by the LED chip and that isexcited by the light from the LED chip, and a light-transmissive resinthat supports the phosphorescent substance inside a package.

The LED chip is an LED element that has side face portions and a topface portion, and the side face portions have sloped faces that areinclined in a convex shape toward the opening in the package.

The phosphorescent substance is preferably disposed in the form of alayer over the bottom face of the package so as to cover all or part ofthe side face part of the LED chip.

SUMMARY OF THE INVENTION

The present disclosure relates to a light emitting device. The lightemitting device includes a flip-chip mounted type light emittingelement, a phosphor-containing member, and a first reflecting member.The flip-chip mounted type light emitting element has a pair ofelectrodes disposed on a bottom surface side. The phosphor-containingmember is provided at least above the light emitting element andseparated from the light emitting element. The first reflecting memberis configured to cover the phosphor-containing member. An opening is inat least one of side faces of the light emitting device, the openingextracting light emitted from the light emitting element and light whosewavelength is converted by the phosphor-containing member.

A method for manufacturing a light emitting device includes: providing alight emitting element having a pair of electrodes disposed on a bottomsurface side; forming a phosphor-containing member at least above thelight emitting element, the phosphor-containing member being separatefrom the light emitting element; forming a first reflecting member thatis configured to covers the phosphor-containing member; and forming, onat least one side face of the light emitting device, an opening forextracting light whose wavelength is converted by thephosphor-containing member and light emitted from the light emittingelement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged vertical cross section of the light emittingdevice according to Embodiment 1 of the invention;

FIG. 2 is an enlarged plan view of the light emitting device accordingto Embodiment 1 of the invention;

FIG. 3 is an enlarged vertical cross section of the light emittingelement when it has been flip-chip mounted on the substrate, before theformation of the light-transmissive member, the phosphor layer, and thefirst reflecting member of the light emitting device according toEmbodiment 1 of the invention;

FIG. 4a is a diagram illustrating the step in a method for manufacturingthe light emitting device according to Embodiment 1 of the invention;

FIG. 4b is a diagram illustrating the step in a method for manufacturingthe light emitting device according to Embodiment 1 of the invention;

FIG. 4c is a diagram illustrating the step in a method for manufacturingthe light emitting device according to Embodiment 1 of the invention;

FIG. 4d is a diagram illustrating the step in a method for manufacturingthe light emitting device according to Embodiment 1 of the invention;

FIG. 4e is a diagram illustrating the step in a method for manufacturingthe light emitting device according to Embodiment 1 of the invention;

FIG. 5 is an enlarged plan view of when numerous light emitting devicesaccording to Embodiment 1 of the invention have been formed on anaggregate substrate;

FIG. 6a is enlarged vertical cross section of when numerous lightemitting devices have been formed on an aggregate substrate,illustrating the method for manufacturing the light emitting deviceaccording to Embodiment 1 of the invention;

FIG. 6b is enlarged vertical cross section of when numerous lightemitting devices have been formed on an aggregate substrate,illustrating the method for manufacturing the light emitting deviceaccording to Embodiment 1 of the invention;

FIG. 7 is an enlarged vertical cross section of the light emittingdevice pertaining to a modification example of the light emitting deviceaccording to Embodiment 1 of the invention;

FIG. 8 is an enlarged plan view of the light emitting device accordingto another modification example of Embodiment 1 of the invention;

FIG. 9 is a detail vertical cross section of the light emitting deviceaccording to Embodiment 2 of the invention;

FIG. 10 is an enlarged vertical cross section of the light emittingdevice according to Embodiment 3 of the invention;

FIG. 11 is an enlarged vertical cross section of the light emittingdevice according to Embodiment 4 of the invention;

FIG. 12 is n enlarged vertical cross section of the light emittingdevice according to Embodiment 5 of the invention; and

FIG. 13 is an enlarged vertical cross section of the light emittingdevice according to Embodiment 6 of the invention.

DETAILED DESCRIPTION OF EMBODIMENT

With the semiconductor device and a method for manufacturing thesemiconductor device by the present disclosure, a slimmer product can beobtained because the light emitting element is flip-chip mounted.Furthermore, since the opening is on a side face, even with a narrowopening, the light output can be increased by increasing the width ofthe light emitting element.

Embodiments of the present invention will now be described throughreference to the drawings.

Embodiment 1 Structure of Light Emitting Device

First, the structure of the light emitting device pertaining toEmbodiment 1 will be described.

As shown in FIGS. 1 and 2, the light emitting device 1 in thisembodiment has a cuboid external shape, and has a bottom face 51 andfour side faces 11, 12, 52, and 53.

The light emitting device 1 comprises a substrate 2 that serves as thebottom face 51, and a light emitting element 3 mounted on the substrate2.

Various kinds of material can be used for the substrate 2, as long asthe substrate 2 has wiring connected to the light emitting element 3.

For example, insulating support substrate such as ceramic (such asAl2O3, AlN) or the like with wiring thereon, or a substrate having resin(such as phenolic resin, epoxy resin, polyimide resin, BT resin(bismaleimide triazine resin), polyphthalamide (PPA)) and a lead framecan be used.

The lead frame here comprises a positive lead electrode and a negativelead electrode.

These electrodes are joined to a p side pad electrode 38 p and an n sidepad electrode 38 n (see FIG. 3) of the light emitting element 3 at theupper face of the substrate 2, via a bonding member 24 (discussedbelow), and serve as terminals that are connected to an external powersupply of the light emitting device 1 at the lower face (rear face) ofthe substrate 2.

The substrate 2 may be one that include wiring without a supportsubstrate. This affords a slimmer light emitting device.

Also, to increase efficiency, both the wiring and the insulating portionof the substrate 2 preferably have high light reflectivity.

The surface of the wiring portion of the substrate 2 can be made fromsilver, gold, rhodium, platinum, or another such material, but silver isparticularly favorable from the standpoint of light reflectivity.

A material with high gloss is even better.

The substrate 2 and the light emitting element 3 are covered with alight-transmissive member 4 that is formed from a transparent resin orthe like and contains substantially no phosphor.

The light-transmissive member 4 may include a diffusing agent or thelike, but preferably does not.

The light-transmissive member 4 is formed directly over the lightemitting element 3, and a phosphor layer 5 that serves as aphosphor-containing member is formed over this.

In this embodiment, the phosphor layer 5 serving as thephosphor-containing member is formed as a layer over thelight-transmissive member 4, but the phosphor-containing member can beconfigured in a variety of other shapes besides that of a layer.

Since the light-transmissive member 4 is thus formed over the lightemitting element 3, the phosphor layer 5 is provided at least above thelight emitting element 3 and separated from the light emitting element3.

A reflecting layer 6 that is made of a reflective resin and that servesas the first reflecting member is provided above the phosphor layer 5.

A variety of materials can be used for the light-transmissive member 4,but after taking light-transmissiveness, reliability, mass production,and so forth into account, a resin material such as a dimethyl siliconeresin, a phenyl silicone resin, a dimethyl/phenyl hybrid silicone resin,an epoxy/silicone hybrid resin, a fluorocarbon resin, an adamantaneresin, an alicyclic epoxy resin, a hybrid epoxy resin, an urethaneresin, polycarbonate (PC), a polymethyl methacrylate (PMMA) can be used,for example.

A silicone resin is particularly preferable because of its goodresistance to heat and light and high optical transmissivity.

The light-transmissive member 4 may contain silica or another suchfiller, or its surface may be textured.

The phosphor-containing member is a member that contains a phosphor thatabsorbs part of the light with the wavelength emitted by the lightemitting element 3, converts this into light of a different wavelength,and emits the resulting light.

In this embodiment, the phosphor-containing member is the phosphor layer5.

The phosphor layer 5 is produced by adding a phosphor to a resin thatserves as a binder.

In addition to a phosphor, the layer may also contain a diffusing agent.

The phosphor layer 5 may have a single-layer structure, or it may have amultilayer structure, or may have a multilayer structure in which eachof the plurality of layers contains different types of phosphor.

As phosphor contained in the phosphor layer, a phosphor based on ayttrium aluminum oxide phosphor activated with Ce (cerium): called YAGphosphor, which can be excited to emit light by light emitted from alight emitting element 3 having an active layer of a nitridesemiconductor can be used.

Specific yttrium aluminum oxide phosphor includes Y3Al5O12Y: Ce (YAG:Ce).

At least one of Ba, Sr, Mg, Ca, and Zn can be contained in the yttriumaluminum oxide phosphor.

In the case where silicon is added to the YAG contained in the phosphorlayer 5, this will suppress crystal growth reactions and result in moreorderly phosphor particles.

Also, when a YAG-based phosphor that is excited by blue light and emitsgreen to yellow light is used together with a nitrogen-containingCa—Al—Si—O—N-based phosphor (oxynitride phosphor) that is excited byblue light and emits orange to red light, then a light emitting element3 capable of emitting blue light can be utilized to obtain a white lightemitting diode with a good color rendering property.

Also, a light emitting device 1 that emits the desired intermediatecolor can be obtained by adding the desired pigment.

A diffusing agent can be added to efficiently diffuse the light emittedby the phosphor and/or the semiconductor light emitting element 3.

Specific examples of material using the diffusing agent include titaniumoxide, silicon oxide, hollow silicon oxide, aluminum oxide, potassiumtitanate, zinc oxide, boron nitride.

A silicone or other such resin powder may be used.

The average particle size of the diffusing agent can be from 0.001 to100 μm, for example, and preferably 0.005 to 50 μm.

A binder is a member used for binding the above-mentioned phosphor ordiffusing agent to the reflecting layer 6 or the light-transmissivemember 4 as the phosphor layer 5.

There are no particular restrictions on the material of this binder,which can be a resin, an inorganic material, or the like.

In the case where a resin is used, a thermosetting resin with excellentlight-transmittance is preferable.

The resin material such as a dimethyl-based silicone resin, aphenyl-based silicone resin, a dimethyl/phenyl hybrid silicone resin, anepoxy/silicone hybrid resin, a fluorocarbon resin, an adamantane resin,an alicyclic epoxy resin, a hybrid epoxy resin, an urethane resin, canbe used, for example.

A silicone resin with good resistance to heat and light and high opticaltransmissivity is particularly preferable.

A glass component may be added to the binder to raise its hardness.

Also, an adhesion-imparting agent may be added to improve adhesiveness.Silane coupling agent, titanate coupling agent, aluminum coupling agentcan be used as the adhesion-imparting agent, for example.

A light-transmissive inorganic material can also be used as a binder. Atleast one of a compound selected from a group comprising of Al2O3, SiO2,ZrO2, HfO2, TiO2, ZnO, Ta2O5, Nb2O5, In2O3, SnO2, TiN, AlN can besuitably used.

The phosphor layer 5 may be formed with a single layer, or may be formedwith a plurality of layers.

Emission color can be easily adjusted by laminating the phosphor layer 5as a plurality of layers.

The reflecting layer 6 is a member for reflecting light emitted by thelight emitting element 3 to the phosphor layer 5 side or the opening 11a of the light emitting device 1.

A material with high light reflection is used for the reflecting layer6.

For instance, it can be a resin layer containing a light reflectingmaterial. For example, the reflecting layer 6 can be one that includesthe light reflecting material and a filler which can be added to theresin such as a silicone resin serving as the binder.

The binder is a member for binding the above-mentioned reflectingmaterial or filler and fix on the phosphor layer 5, as the reflectinglayer 6.

There are no particular restrictions on of the binder of the specificmaterial, and a resin, an inorganic material, or the like can be used.

The resin serving as the binder can be the same as that used for thebinder in the phosphor layer 5.

The reflecting material is a member that reflects the light emitted bythe light emitting element 3.

The same material as that of the diffusing agent used for the phosphorlayer 5 can be used as the reflecting material.

The filler is added for a variety of purposes, such as to raise thestrength of the reflecting layer 6 (a resin layer), or to raise thethermal conductivity of the reflecting layer 6.

Glass fibers, whiskers, aluminum oxide, silicon oxide, boron nitride,zinc oxide, aluminum nitride can be used as the filler, for example.

As discussed above, the light emitting device 1 in this embodiment has acuboid shape, and when the face on the substrate 2 side of the lightemitting element 3 is define to be the bottom face 51, then at least oneof the four side faces 11, 12, 52, and 53 (the side face 11 in thisexample) has the opening 11 a.

That is, the light emitting device 1 in this embodiment is a side faceemitting type of light emitting device that emits light from the opening11 a in the side face 11.

When the side face 11 having the opening 11 a is at the front of thelight emitting device 1, and the side face 12 is on the opposite side,then the phosphor layer 5 and the reflecting layer 6 are formed on theleft and right sides (the side faces 52 and 53 sides), to the rear (theside face 12 side), and above (the upper face 13 side) of the lightemitting element 3 (and of the light-transmissive member 4 surroundingit).

That is, the phosphor layer 5 in this embodiment surrounds the lightemitting element 3.

With this light emitting device 1, light that is wavelength-converted bythe phosphor layer 5 and light from the light emitting element 3 can beextracted from the opening 11 a in the side face 11.

With the light emitting device 1 of the present embodiment, to mount thelight emitting element 3 on the substrate 2, flip-chip mounting isperformed in which the positive and negative electrodes are mountedopposite the substrate 2.

FIG. 3 is a detail vertical cross section of the light emitting element3 in this embodiment which is flip-chip mounted on the substrate 2,before the formation of the light-transmissive member 4, the phosphorlayer 5, and the first reflecting member 6

As shown in FIG. 3, the light emitting element 3 is equipped with asubstrate 32, a semiconductor laminate 33 that is laminated over thesubstrate 32, an n side electrode 34 n, the n side pad electrode 38 n, ap type overall electrode 41, a p type cover electrode 42, an insulatingfilm 43, a p side electrode 34 p, the p side pad electrode 38 p, and aninsulating film 36.

The n side electrode 34 n and the p side electrode 34 p are bothprovided on the same side where the semiconductor laminate 33 of thelight emitting element 3 is provided, which is better suited toflip-chip mounting.

The semiconductor laminate 33 has a laminar structure in which an n typesemiconductor layer 331 composed of a gallium nitride-based compoundsemiconductor, an active layer 332, and a p type semiconductor layer 333are laminated in that order from the substrate 32 side, for example.

The substrate 32 of the light emitting element 3 may be formed from asubstrate material that allows a nitride semiconductor to be epitaxiallygrown, but because flip-chip mounting is involved, the substrate ispreferably light-transmissive so that light can be extracted.

Examples of the material for the substrate include an insulatingsubstrate, such as sapphire (Al2O3) having a main surface of any one ofC plane, R plane, A plane, M plane, spinel (MgAl2O4), and the like, andsilicone carbide (SiC), ZnS, ZnO, Si, GaAs, diamond, and an oxidesubstrate such as lithium niobate and neodymium gallate which arecapable of forming a lattice matching with the nitride semiconductor.

The p side pad electrode 38 p and the n side pad electrode 38 n are padelectrodes used for connection using the bonding member 24 (Au—Sneutectic solder, etc.) or the like in the mounting of the light emittingelement 3 to the substrate 2.

In this embodiment, the p side pad electrode 38 p is electricallyconnected to the surface of the p side electrode 34 p in an opening 36 pof the insulating film 36, and is also provided so as to extend over awide range on the insulating film 36.

The n side pad electrode 38 n is electrically connected to the surfaceof the n side electrode 34 n in an opening 36 n of the insulating film36, and is also provided so as to extend over the insulating film 36.

That is, the p side pad electrode 38 p and the n side pad electrode 38 nboth extend over the insulating film 36, which is provided above the ptype semiconductor layer 333.

Consequently, the surface area of the n side pad electrode 38 n can belarger than that of the exposed part of the n type semiconductor layer331, which improves enhance bonding property of the n side pad electrode38 n to the substrate 2.

Furthermore, in this embodiment, the p side pad electrode 38 p and the nside pad electrode 38 n have substantially the same height from theupper face of the substrate 32.

Therefore, the upper ends of the p side pad electrode 38 p and the nside pad electrode 38 n, which are the connected parts in flip-chipmounting, are at the same height, so there is no step between the p-sideelectrode connection face and the n-side electrode connection face,making mounting easier.

The p side pad electrode 38 p and the n side pad electrode 38 n arepreferably metal films that have good adhesion to the p side electrode34 p and the n side electrode 34 n to which they are provided, and thathave low electrical resistance overall.

An example of a metal film that can be used is a multilayer film inwhich titanium, nickel, and gold are laminated in that order from thelower layer side.

When the p side pad electrode 38 p and the n side pad electrode 38 nextend over a wide area as in this embodiment, the heat dissipation ofthe light emitting element 3 can be improved.

The location and surface area over which the p side pad electrode 38 pand the n side pad electrode 38 n extend can be determined taking intoaccount ease of mounting and heat dissipation.

The insulating film 36 is a film with an insulating property, whichcovers the exposed surface of the semiconductor laminate 33, andfunctions as an antistatic film and a protective film for thesemiconductor laminate 33. The material of the insulating film 36 can bean oxide of silicon, titanium, tantalum, niobium, or the like.

In this embodiment, the insulating film 36 is made up of two layers: asecond insulating film 362 and a first insulating film 361 that isprovided on the second insulating film 362 so as to cover the side facesand the upper faces of the p side electrode 34 p and the n sideelectrode 34 n except for at the openings 36 p and 36 n.

Accordingly, the insulating film 36 is formed thinner at the upper facesof the p side electrode 34 p and the n side electrode 34 n than in otherareas.

The first insulating film 361 and the second insulating film 362 areboth formed from the same material, and are substantially integratedfilms.

In FIG. 3, the light emitting element 3 is preferably joined on thesubstrate 2 using Au—Sn eutectic solder or another such solder (bondingmember) 24.

Alternatively, a bump composed of gold or another such metal may be usedas the bonding member 24 that joins the light emitting element 3 and thesubstrate 2 together.

The space between the lower part of the light emitting element 3 and thesubstrate 2 is preferably filled with an insulating resin or anothersuch underfill material in order to improve the joint strength.

With the light emitting device 1 in this embodiment, the lightextraction face is a side face of the light emitting device 1, such asthe side face 11.

The phosphor layer 5 is provided at least above the light emittingelement 3, and separated from the light emitting element 3, and the topof the phosphor layer 5 is covered by the reflecting layer 6.

Also, with the light emitting device 1 in this embodiment, when the sideface 11 on the opening 11 a side is define to be the front and the sideface 12 on the opposite side is the rear, the inner wall 55 of thereflecting layer 6 has a shape that continuously curves to the inside,so as to surround the rear (the side face 12 side), the top (the upperface 13 side), and the left and right sides (the side faces 52 and 53sides) of the light emitting element 3.

Also, the light emitting element 3 is provided so that the centerposition of the light emitting element 3 (broken line 14 b) in thelongitudinal direction (the left and right direction in FIG. 1) isfurther to the rear (the left side in FIG. 1) by a distance b than thecenter position of the light-transmissive member 4 (the one-dot chainline 14 a, which is the center portion of the distance a in FIG. 1) inthe longitudinal direction (the left and right direction in FIG. 1).

Consequently, the light emitting element 3 is provided behind theopening 11 a, so there will be less light that undergoes multiplereflection in the opposite direction from the opening 11 a, and this canimprove the light extraction efficiency of the light emitting device 1.

Method for Manufacturing Light Emitting Device

Next, the method for manufacturing the light emitting device 1 will bedescribed based on the Figures.

FIGS. 4A to 4D are diagrams illustrating the steps in a method formanufacturing the light emitting device 1 according to Embodiment 1 ofthe invention.

FIG. 5 is a detail plan view of when numerous light emitting devices 1have been formed on an aggregate substrate 2.

First Step

As shown in FIG. 4A, first, the light emitting elements 3, which areblue LED chip comprising a light-transmissive sapphire substrate andnitride semiconductor layers, are die-bonded to the substrate 2 thatprepared as an aggregate substrate by flip-chip mounting as discussedabove.

In this embodiment, as shown in FIGS. 4a to 4d and 5, a plurality oflight emitting elements 3 are mounted in a matrix, separated from oneanother, on the substrate 2.

Each light emitting element 3 is mounted so that the center position(the broken line 14 b in FIG. 1) of the light emitting element 3 in thelongitudinal direction of the substrate 2 will be further to the rearthan the center of the substrate 2 in the longitudinal direction (theone-dot chain line 14 a in FIG. 1) after these have been made into thelight emitting device 1.

Second Step

Next, as shown in FIG. 4B, the light-transmissive member 4 is formed onthe substrate 2 on which the light emitting element 3 are mounted, so asto cover the surface of the light emitting element 3 and the substrate2.

As shown in FIGS. 4a to 4d and 5, in this embodiment, a plurality ofsubstantially semiellipse spherical light-transmissive members 4 thatcover two adjacent light emitting elements 3 are formed.

These light-transmissive members 4 are formed such that when the sideface 11 on the opening 11 a side is define to be the front and the sideface 12 on the opposite side is define to be the rear after the lightemitting device 1 has been produced, then the inner wall 55 of thereflecting layer 6 has a shape that continuously curves to the inside,so as to surround the rear (the side face 12 side), the top (the upperface 13 side), and the left and right sides (the side faces 52 and 53sides) of the light emitting element 3 as shown in FIG. 1. Thelight-transmissive members 4 can be formed, for example, by transfermolding, by compression molding, by potting a resin with high adhesionand forming it into a dome shape, by drawing with a resin dispensed froma dispenser, by mask printing, by a method in which a previously moldedresin is cut and diced, or by a combination of these methods.

Third Step

Next, as shown in FIG. 4C, the phosphor layer 5 is formed oversubstantially the entire surface so as to cover the top of thelight-transmissive member 4. Examples of methods for forming thephosphor layer 5 include a method in which a resin, or a sol of aninorganic substance, or the like containing a phosphor is mixed with asolvent and then sprayed, a method in which a phosphor-containing sheetis attached, and the method described in the second step above, but itis preferable to use a method with which the entire phosphor layer 5 canbe made thinner and/or the phosphor can be formed more densely.

This reduces variance in the emission color of the light emitting device1. Preferable examples of such a method include the above-mentionedspraying, and electrodeposition.

Electrodeposition can be performed in such a procedure as that analuminum film is formed as an electrodeposition electrode by sputteringover the light-transmissive member 4, a phosphor is electrodepositedover this aluminum film, and then the aluminum film is oxidized to berendered transparent, among other possible means.

Fourth Step

Next, as shown in FIG. 4D, the reflecting layer 6 (serving as areflecting member) is formed over the phosphor layer 5.

There are no particular restrictions on the formation method, but when alight reflecting resin is used, examples include transfer molding andcompression molding.

Fifth Step

Next, as shown in FIG. 4E, the product formed in FIG. 4D is separated orcut into units that will serve as a single light emitting device 1, thatis, so as to include the substrate 2, the light-transmissive member 4,the phosphor layer 5, and the reflecting layer 6, thereby producingindividual light emitting devices 1.

More specifically, the product is diced along the one-dot chain lines 15shown in FIG. 5, that is, along the approximate center lines of thereflecting layers 6 between the light emitting elements 3 and the centerlines of the light-transmissive members 4 that are substantiallyelliptical in plan view, which produces a plurality of individual lightemitting devices 1.

In this embodiment, the cut faces of the light-transmissive members 4become openings in the side faces 11 that are the light extraction facesof the light emitting devices 1.

Also, when the light-transmissive members 4 are formed on the aggregatesubstrate 2 by transfer molding, and the phosphor layer 5 is formed overthe light-transmissive members 4 as in this embodiment, as shown in FIG.6A, joint portions 16 are formed between areas adjacent light emittingelements 3 and will not be on the light extraction side (such as theportion that will become the rear or the side face of each lightemitting device 1), in a state in which the light-transmissive members 4and the phosphor layer 5 are provided on the aggregate substrate 2.

In this case, the phosphor layer 5 can be formed in the step of FIG. 4Cafter the portion of the light-transmissive members 4 have been removedby dicing or the like (sixth step) as shown in FIG. 6B, after the secondstep in FIG. 4B and before the third step in FIG. 4C.

FIG. 7 is a detail vertical cross section of a light emitting device101, which is the light emitting device in another embodiment.

With the light emitting device 101 in the embodiment shown in FIG. 1,which is manufactured through the above-mentioned steps up to the sixthstep, the leakage of light from the light-transmissive joint portions 16can be prevented with the configuration in FIG. 7, in which themanufacture does not involve the sixth step.

The rest of the configuration of the light emitting device 101 in FIG. 7is similar to that of the light emitting device 1 in FIG. 1, the samenumbering as in FIG. 1 is used, and explanation for the similar partsare abbreviated. The light emitting device 101 shown in FIG. 7 can bemanufactured less expensively by batch molding.

With the manufacturing method in this embodiment, when the face of thelight emitting device 1 on the substrate 2 side is define to be thebottom face 51, the side face 11 of the light emitting device 1 will bethe light extraction side of the light emitting element 3 (see FIG. 4E).

Also, in the step in FIG. 4C, when this light extraction side (the sideface 11) is define to be the front and the opposite side (the side face12) is define to be the rear, the phosphor layer 5 and the reflectinglayer 6 are provided on the left and right sides, to the rear, and tothe front of the light emitting element 3.

Furthermore, in the step in FIG. 4A, the light emitting elements 3 ismounted in a position that will be further to the rear than the centerof the individual substrate 2 in the longitudinal direction (the one-dotchain line 14 in FIG. 1).

With the light emitting device 1 manufactured by above process, part ofblue light that emitted from the light emitting element 3 will beconverted by the phosphor layer 5 into yellow light, and then reflectedby the reflecting layer 6 to the side of the light-transmissive member4.

The blue light and yellow light will separately be extracted from theopening in the side face 11, and partially color-mixed white light willbe extracted from the opening in the side face 11.

With the light emitting device 1 and its manufacturing method describedabove, since the light emitting element 3 is flip-chip mounted on thesubstrate 2, bonding wire or the like can be omitted, so the lightemitting device 1 can be made slimmer.

Also, since the light extraction face is the side face 11 of the lightemitting device 1, a wide light emitting element 3 can be mounted eventhough the light extraction face is small.

Thus, a wider light emitting element 3 can be mounted to increase thelight output.

Thus, with the light emitting device 1 in Embodiment 1, a slimmer lightemitting device 1 can be obtained and the light output can be increased.

Also, with the light emitting device 1 in Embodiment 1, since the lightemitting element 3 and the phosphor layer 5 are separated so that theyare not in contact, there is less return light from the phosphor layer 5to the light emitting element 3, and the light extraction efficiency ofthe light emitting device 1 can be increased.

Furthermore, since part of the light emitted from the light emittingelement 3 is extracted without being incident on the phosphor layer 5,blue light can be extracted efficiently, and the light extractionefficiency of the light emitting device 1 can be increased.

Moreover, with the light emitting device 1 in Embodiment 1, since thelight incident on the phosphor layer 5 is reflected by the reflectinglayer 6, there is less multiple reflection within the phosphor layer 5.

Accordingly, the absorption of light within the phosphor layer 5 can bereduced.

Also, since the light incident on the phosphor layer 5 is reflected bythe reflecting layer 6, variance in the color of the light from thelight emitting device 1 caused by variance in the thickness of thephosphor layer 5 can also be reduced.

That is, as long as the phosphor layer 5 has at least a certainthickness, the color of the light obtained from the phosphor layer 5will be saturated (that is, just light that contains substantially nolight of the emission wavelength of the light emitting element, andwhose wavelength has been converted by the phosphor can be obtained), sothe color of the resulting white light obtained from the light emittingdevice 1 can be made consistent, and the color yield of the product canbe raised.

The embodiment of the above can be modified in various ways.

FIG. 8 is a detail plan view of the light emitting device 1 according tomodification of Embodiment 1.

As in the example in FIG. 8, the outer shape of the light-transmittivemember 4 and the phosphor layer 5 may be angular, such that the left andright sides and the rear side of the light emitting device 1 aresubstantially straight lines.

Also, a reflecting layer that serves as a second reflecting member(hereinafter referred to as the “second reflecting layer”) may be formedbetween the phosphor layer 5 and the reflecting layer 6.

The reflecting layer can be formed by following step, for example, inbetween the step in FIG. 4C and the step in FIG. 4D, a metal film withhigh optical reflectivity, such as silver, aluminum, platinum, orrhodium, or a DBR (Distributed Bragg Reflector) mirror may be formedover the phosphor layer 5

When a reflecting layer that serves as a second reflecting layer is thusformed, the reflecting layer 6 need not be formed.

This point is also applicable to Embodiments 2 and other embodiments(described below).

Embodiment 2

FIG. 9 is a detail vertical cross section of the light emitting device 1pertaining to Embodiment 2 of the present invention.

In FIG. 9, those members shared with Embodiment 1 are numbered the sameand their detail description will be abbreviated.

The manufacturing method, unless otherwise specified, is also the sameas in Embodiment 1.

The difference in the structure and manufacturing method of the lightemitting device 1 in this embodiment from those of the light emittingdevice 1 in Embodiment 1 is that the substrate 32, which is thesubstrate for growing the semiconductor layer as the light emittingelement 3 that is flip-chip mounted on the substrate 2, is removed.

As flip-chip mounting is performed just as in Embodiment 1, and thegrowth substrate is separated and removed from the light emittingelement 3 by laser liftoff or another such method, the light emittingelement 3 can be even slimmer than in Embodiment 1.

Thus separating the growth substrate and making the uppermost face ofthe light emitting element 3 the semiconductor layer affords an evenslimmer light emitting device 1.

Also, since the light emitting element 3 has no substrate 32, lightextraction efficiency of the light emitting element 3 can be improved,thus the light extraction efficiency of the light emitting device 1 canbe raised.

Embodiment 3

FIG. 10 is a detail vertical cross section of the light emitting device1 pertaining to Embodiment 3 of the present invention.

In FIG. 10, those components shared with Embodiment 1 are numbered thesame and their detail description will be abbreviated again.

The manufacturing method, unless otherwise specified, is also similar tothat in Embodiment 1.

The difference in the structure and manufacturing method of the lightemitting device 1 in this embodiment from those of the light emittingdevice 1 in Embodiment 1 is that the light-transmissive member 4 and thephosphor layer 5 are not formed on a rear face 3 b of the light emittingelement 3 side which is on the opposite side from an opening 11 (lightemitting face), and that this rear face 3 b is in direct contact withthe reflecting layer 6.

Such configuration can be obtained by following method, that is, in thesteps in FIGS. 4b and 4c , the light-transmissive member 4 and thephosphor layer 5 are not formed on the rear face 3 b side of the lightemitting element 3, and in the step in FIG. 4D, the reflecting layer 6is formed so that the rear face 3 b will be in direct contact with thereflecting layer 6.

This reflecting layer 6 can be formed, for example, from a lightreflecting material, such as by potting a white resin, at the rear face3 b of the light emitting element 3.

Consequently, light outputted from the light emitting element 3 on theopposite side from the light extraction side (the side face 11 side) canbe efficiently reflected by the reflecting layer 6.

Also, the material formed in contact with the rear face 3 b of the lightemitting element 3 may be an underfill material mentioned above ratherthan the reflecting layer 6.

Embodiment 4

FIG. 11 is a detail vertical cross section of the light emitting device1 pertaining to Embodiment 4 of the present invention.

In FIG. 11, those members shared with Embodiment 1 are numbered the sameand their detail description will be abbreviated.

The manufacturing method, unless otherwise specified, is also similar tothat in Embodiment 1.

The difference in the structure and manufacturing method of the lightemitting device 1 in this embodiment from those of the light emittingdevice 1 in Embodiment 1 is that, when the face 3 a on the opening 11 aside of the light emitting element 3 is define to be the front and theface 3 b on the opposite side is define to be the rear, the inner wall55 of the reflecting layer 6 on the rear face 3 b side has a concaveshape as viewed from the light emitting element 3 side, that is, theportion 55 a of the inner wall 55 that touches the substrate 2 isrounded so as to protrude further to the front side than the portion 55b above.

To obtain such a configuration, part of the phosphor layer 5 and thereflecting layer 6 on the rear face 3 b can be formed prior to theformation of the light-transmissive member 4 in FIG. 4B, so that thephosphor layer 5 on the rear face 3 b side of the light emitting element3 will have this shape. This configuration allows the light emitted onthe opposite side from the light extraction side (the side face 11 side)of the light emitting device 1 to be effectively reflected by thereflecting layer 6 with this shape.

Embodiment 5

FIG. 12 is a detail vertical cross section of the light emitting device1 pertaining to Embodiment 5 of the present invention. In FIG. 12, thosemembers shared with Embodiment 1 are numbered the same and their detaildescription will be abbreviated again. The manufacturing method, unlessotherwise specified, is also similar to that in Embodiment 1.

The difference in the structure and manufacturing method of the lightemitting device 1 in this embodiment from those of the light emittingdevice 1 in Embodiment 1 is that a plurality of (two in the example inFIG. 12) light emitting elements 3 are mounted on a single lightemitting device 1. This raises the light output of the light emittingdevice 1.

Embodiment 6

FIG. 13 is a detail vertical cross section of the light emitting device1 pertaining to Embodiment 6 of the present invention.

In FIG. 13, those components shared with Embodiment 1 are numbered thesame and their detail description will be abbreviated.

The manufacturing method, unless otherwise specified, is also similar tothat in Embodiment 1.

The difference in the structure and manufacturing method of the lightemitting device 1 in this embodiment from those of the light emittingdevice 1 in Embodiment 1 is that the reflecting layer 6 is in the formof a thin film, and a package member 7 is provided that covers thereflecting layer 6 and serves as the outer face of the light emittingdevice 1.

When the reflecting layer 6 is provided between the package member 7 andthe light-transmissive member 4 as in this embodiment, the material ofthe package member 7 is not limited to one having high opticalreflectivity, and can be selected from a wide variety of materials.

For instance, an epoxy resin, PPA, or another such material that hasblack color and is relatively inexpensive can be used preferably.

There are no particular restrictions on the method for forming thepackage member 7, and it can be formed by the method similar to that ofthe reflecting layer 6 serving as the above-mentioned first reflectingmember. In this embodiment, the reflecting layer 6 can be formed usingthe similar material and manufacturing method as the above-mentionedsecond reflecting layer or the reflecting layer 6 serving as the firstreflecting member in Embodiment 1.

It should go without saying that the embodiments described above do notlimit the present invention.

That is, it is to be understood that although the present invention hasbeen described with regard to preferred embodiments thereof, variousother embodiments and variants may occur to those skilled in the art,which are within the scope and spirit of the invention, and such otherembodiments and variants are intended to be covered by the followingclaims.

For example, the light emitting device 1 that is an embodiment of thepresent invention may be such that the light-transmissive members 4 ofthe joint portions 16 in the light emitting device 1 in FIG. 7 may beremoved, and the joint portions 16 become the substrate 2, the phosphorlayer 5, and the reflecting layer 6 from below.

INDUSTRIAL APPLICABILITY

The light emitting device according to the present disclosure can beused for various kinds of light sources, such as illumination lightsources, light sources for various kinds of indicators, light sourcesfor automobile use, light sources for displays, back light sources forliquid crystal displays, light sources for sensors, signals, automobileuse, channel control characters for channel boards.

What is claimed is:
 1. A light emitting device comprising: a flip-chipmounted type light emitting element having a pair of electrodes disposedon a bottom surface side; a phosphor-containing member provided at leastabove the light emitting element and separated from the light emittingelement; a first reflecting member configured to cover thephosphor-containing member, and an opening in at least one of side facesof the light emitting device, the opening extracting light emitted fromthe light emitting element and light whose wavelength is converted bythe phosphor-containing member.
 2. The light emitting device accordingto claim 1, further comprising a light-transmissive member containingsubstantially no phosphor, the light emitting element is covered by thelight-transmissive member, and the phosphor-containing member isprovided over the light-transmissive member.
 3. The light emittingdevice according to claim 2, both of the light-transmissive member andthe phosphor-containing member are exposed at the opening.
 4. The lightemitting device according to claim 1, wherein the phosphor-containingmember surrounds the light emitting element.
 5. The light emittingdevice according to claim 1, wherein when the side face with the openingis defined to be the front and the side face on the opposite side isdefined to be the rear, the first reflecting member has an inner wallwith a shape that continuously curves inwardly so as to surround therear, top, left and right sides of the light emitting element, and thelight emitting element is provided closer to the rear than a center ofthe light emitting device in the longitudinal direction.
 6. The lightemitting device according to claim 1, wherein the light emitting elementis in contact with the first reflecting member on a face on opposite tothe opening.
 7. The light emitting device according to claim 1, whereinan inner wall of the first reflecting member is bent so as to have aconcave shape as viewed from the light emitting element.
 8. The lightemitting device according to claim 1, wherein a plurality of lightemitting elements are mounted.
 9. The light emitting device according toclaim 1, further comprising a second reflecting member, and the secondreflecting member is provided between the phosphor-containing member andthe first reflecting member.
 10. The light emitting device according toclaim 9, the light emitting element is in contact with the secondreflecting member on a face on an opposite to the opening.
 11. The lightemitting device according to claim 1, wherein an uppermost face of thelight emitting element is a semiconductor layer.
 12. A method formanufacturing a light emitting device, the method comprising: providinga light emitting element having a pair of electrodes disposed on abottom surface side; forming a phosphor-containing member at least abovethe light emitting element, the phosphor-containing member beingseparate from the light emitting element; forming a first reflectingmember that is configured to covers the phosphor-containing member; andforming, on at least one side face of the light emitting device, anopening for extracting light whose wavelength is converted by thephosphor-containing member and light emitted from the light emittingelement.
 13. The method for manufacturing a light emitting device ofclaim 12, further comprising forming a light-transmissive member afterthe mounting of the light emitting element and before the formation ofthe phosphor-containing member.
 14. The method for manufacturing a lightemitting device of claim 12, wherein the mounting of the light emittingelement includes mounting a plurality of light emitting elements onto anaggregate substrate.
 15. The method for manufacturing a light emittingdevice of claim 13, wherein the formation of the light-transmissivemember includes forming the light-transmissive member that covers theplurality of light emitting elements; and the formation of thephosphor-containing member includes forming the phosphor-containingmember that covers the light-transmissive member.
 16. The method formanufacturing a light emitting device of claim 15, wherein the formationof the opening includes cutting the aggregate substrate, thelight-transmissive member, and the phosphor-containing member.